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Galant eating ECU's

mitsu90

Well-known member
Joined
Nov 16, 2005
Messages
706
Location
Illinois
I am having an issue with my car burning up ECU's. I am on my 3rd one in the last 5 months.

It's always the same thing, middle ECU plug ends up with green coronation on it and the caps go boom.This has got to be more then just bad ECU's.


Anyone know what could be causing this problem? /ubbthreads/images/graemlins/confused.gif
 

Do you possibly have a windshield leak that is getting water in the ECU? Did you inspect/replace the capacitors on each ECU before installing it? What is your alternator voltage? Answers please.....
 

mitsu90

Well-known member
Joined
Nov 16, 2005
Messages
706
Location
Illinois
alt. is brand new this year. haven't noticed a window leak. didn't inspect the caps prior to use.

the first ecu was my eprom and I just figured it was my fault for not dealing with the caps.

2nd ecu I got from a friend and he claimed to have had the cap replaced within the last year.

3rd ecu I pulled from a parts car and has only been in my car for a month. and only driven on for a week.I just pulled the cover off this one and the board looks brand new, but around one cap is a blackish burn mark and around another it looks like it puked on the board.

and like I said the middle ecu plug it covered in green gunk.

I am electrical retarded so I have no clue what could be doing this..I guess it's possible that I got a hold of 3 almost dead ecu's.
 

Quote:
didn't inspect the caps prior to use


Well, I think there you have your answer. Using an ECU without replacing the caps is like playing Russian Roulette. Its just a matter of time until things melt down. The second ECU, the one your friend said he had replaced the caps, I would write that one off as probably a victim of acid residue damage. Too many people only replace the caps, and don't take the time to clean up all the acid, and its inevitable that the ECU will eventually malfunction. The acid gets under all the components and continues to do its nasty work, even years after the caps have been replaced.
If you didn't flush the connector off well with some type of electrical cleaner, the green stuff is probably residue from one of the first ECU's. Either way, I would recommend you clean it well with a good contact cleaner to neutralize the acid.
Now you know why I only deal in 1994 ECU's. I won't touch ones with acid damage, except to remove parts from them and then throw their acid-eaten carcass in the trash! /ubbthreads/images/graemlins/devil.gif
My ECU's might cost a little more than one off eBay, but you are getting one that has NEVER had any acid leakage, and never will. That little peace of mind is priceless, IMHO.
 

mitsu90

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Joined
Nov 16, 2005
Messages
706
Location
Illinois
you think any of these can be fixed. I can't afford to buy another ecu.
 

thecman02

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Joined
Nov 3, 2007
Messages
917
Location
Kalamazoo,MI
one of mine was malfunctioning till terry fixed it up. It works just fine again. If anyone can help you its him.
 

Terry Posten

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Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
I can't garrentee work from leaked on or blown up ECUs. If you get them to me before bad things happen, I can help.

As Keydiver said, once acid happens, it is VERY hard to fix it so that bad things never happens.

Your best bet is to start fresh with a known good unit from Keydiver. I know it sucks that good money has been been lost but don't keep making the same mistake.

Sorry for your troubles.
 

mitsu90

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Joined
Nov 16, 2005
Messages
706
Location
Illinois
yea it defiantly not fun dumping money down the drain /ubbthreads/images/graemlins/banghead.gif
 

mitsu90

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Nov 16, 2005
Messages
706
Location
Illinois
I just want to be 100% sure before I spend any more money on ecus.


would hate to kill another one if it's something else causing the problem.
 

mitsu90

Well-known member
Joined
Nov 16, 2005
Messages
706
Location
Illinois
need an ecu..it ate the last one just sitting in my driveway for a week /ubbthreads/images/graemlins/banghead.gif
 

Quoting 1941Galant:
If I remember correctly can't a bad ISC kill an ecu?



Very Yes.
 

Terry Posten

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Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
The first issue that comes from leaking caps is under the 47uf cap. The acid eats the copper and then allows the power and ground traces to short out that causes any number of things.

The other issue is that the copper traces under the 100uf caps get eaten and the cap stops filtering the power to the board. This can cause the processor to have glitches and other issues.

All around, it is a bad thing.

Even if you see no traces of acid they must be replaced ASAP.

To tell if you have an untouched ECU, read the print on the side of the 47 and 100uf caps. If the brand name is "Rubycon", they are stock and MUST be replaced. The 22uf caps is a "nichicon" cap and is a good part but I replace it anyway to allow for cleaning under it because the acid runs under it and the only way to clean is to remove it.

The other thing that is done most of the time is the large black diode comes out to help with access to the board and on rare occasions the IC110 board has to be removed and cleaned due to corrosion on the legs.

Simply replacing the caps is NOT good enough. You must eliminate all traces of acid. Even the stuff you don't see. And sometimes even that is not enough. It all depends on the extent of the acid running over the board.
 

stevep

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Joined
Oct 23, 2004
Messages
416
Location
St. Charles, IL USA
I'd really like to see what's going on here (pictures?) but the green around the connector has to be a big clue because the caps going bad typically isn't going to cause this.

The only time I see any signs of coloration on the edge connectors is when liquid has reached the connectors.
 
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